Cellulose-ether composition



Patented Se t. 8, 1925. I

UNITED STATES" 1.5 2.806 PATENT oFmcE'.

30ml I. DONOE'UE, Olff ROCHESTER, NEW YORK, ASSIGIIOB TO EASTMAN KODAKCOIYANY, OI ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

ceLLuLosa-E'rnm comosruou.

Io Drawing.

- To all whom it may concern:

Be it known that I, JOHN M. DONOHUE, a

' citizen of the United-States of America, re-

siding at Rochester, in the county of Monroe 6 and State of New York,have invented certain new and useful Improvements in Cellulose-EtherCompositions, of which the following is a full, clear,andexactspecification.

This invention relates to solvents for making strong solutions ofcellulose 'ether and also relates to the cellulose ether compositionsroduced' by the aid of such solvents. One 0 ject of my invention is toprovide a solvent'which Wlll dissolve such large proportions ofcellulose ethers that thick or viscous fiowable solutions may beobtained for use in plastic and film making arts.

Another object of my invention is to provide i a cellulose ethersolution which may be manufactured into strong, flexible, transpari cutfilms on the machines and by the methods now in use. Other objects willhereinafter appear. I

In U. S. Patent No. 1,188,376, Lilienfeld, June 20, 1916, there aredisclosed a series of alkyl ethers of cellulose. Certain of these arepractically insoluble in water, and my invention relates, but is notlimited, to the ethers having that property. While cellulose ethers formthin solutions in the formic acid esters of the lower monohydroxyaliphatic alcohols, it has been found that such single solvents by'themselves are inadequate to produce the thick flowable compositions ordopes adapted for use in the manufacture of photographic film base bythe customary methods or adapted to the other plastic arts.

I have discovered, however, that the for- 40 mates of the lowermonohydroxy aliphatic alcohols have strong latent solventpowers,

these powers being brought out bysuitable common solvents. By lowermonohydroxy aliphatic alcohols I include those having less than 6 carbonatoms. Among the common solvents that may be used are benzol, acetoneand the lower monohydroxy aliphatic alcohols. In the formation of filmmethyl alcohol is referred.

While the ingredients may be mixed in widely varying proportions, it isnoted, by

. way of example, that a particularly useful composition can be preparedby mixin equal parts by weight of the formate an the common solvent. Inthe preferred form able do Application filed February 24, 1923. Serialllo. 621,087.

of my invention, I dissolve 1 part by wei ht:

hol. The ingredients by themselves are not sufficiently powerful to makeproperly flowpes of this strength. Of course, the proportion of mixedsolvent or the proportion of theovolatile ingredients may be increasedto adapt the composition to the lacquering art, as will be understood bypersons'skilled therein.

Other substances which impart additional suppleness, orincombustibility, or other qualitles to the film may also be added tothe dope, such, for instance, as triphenyl or tricresyl phosphate,monochlornaphthalene, I

camphor, etc. The ingredients are of the ordinary commercial type andsufficiently purified for the process of film manufacture, so as to givea dope yielding films having the proper relative freedom from color. The

viscous-flowable dope above described can be used in connection with theusual film-form- 111g apparatus without the necessity of expensivealterations in the latter.

In the formation of a film by spreading and drying the hereinabovedescribed composition a considerable amount of the formic acid esterremains behind, because of its relativelylow volatility, the volatilitybeing less in the esters which have the greater number of carbon atomsin the alkyl radical. The esters impart useful plastifying and otherproperties to. the film, which is normally flexible and transparent.Since the ratio of the weight of alkyl formate to the weight of thecellulose other can be made much greater by the use of my mixed solventinstead of using the formic acid ester alone as a solvent, it followsthat 9. correspondingly greater proportion of the formate will bepresent in the finished film than when the cellulose ethers' aredissolved in the formic acid esters alone.

Having .thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. A composition of matter comprising cellulose ether and a formic acidester of a lower monohydroxy ali hatic alcohol and a common solventwhich rings out the latent solvent power of the ester.

2;, composition of matter comprising cellulose ether and methyl foi'matehomogeneously mixed together in unprecipitated '4. A composition ofmatter comprising cellulose ether dissolved in a mixture ofsubstantially equal parts by weight of a lower monohydroxy aliphaticalcohol and a formic acid ester of a lower monohydroxy aliphaticalcohol.

5. A composition of matter comprising 2 parts by weight ofwater-insoluble ethyl cellulose, 7 parts of methyl formate and 7 I partsof methyl alcohol.

'6. As an article of manufacture, a film comprising cellulose other andmethyl formate.

7. As an article of manufacture, a deosited, transparent, flowable filmcomprislng cellulose ether and a formic acid ester of a lowermonohydroxy aliphatic alcohol,

the proportion of said ester in said film being greater than .themaximum proportion deposit-able in a transparent film from a solution ofsaid cellulose ether in said ester alone. Signed at Rochester,

day of February, 1923.

JOHN M. DONOHUE.

New York, this 16

